Please note: Staff working hours override business working hours, and the options for service working hours in the settings of your services act like a mesh or subset of your staff working hours.
e.g. You could have staff work from 12pm till 5pm and you could have service based working hours go from 12pm till 1pm - this will mean that the service is only available between 12-1.
e.g. 2. If you have staff working hours set from 12pm till 5pm and service working hours set from 9am till 11am, then there will be NO availability as there is no overlap between staff and service working hours.
It sure can, head into your name in the top right corner > settings > working hours > adjust days you would like to work by toggling the day and adjust times of the day.
You can adjust staff hours and breaks using this article